1. Field of the Invention
The present invention relates to a process camera apparatus which is cpable of conducting, as required, both the line photographing of images such as letters or characters and halftone photographing of picture and patterns on a photosensitive material. The invention is concerned also with a process camera apparatus which is provided with a guide means for smoothly transporting the photosensitive material onto the transparent platen of the image take-up section.
2. Description of the Prior Art
A process camera apparatus capable of performing both line photographing and halftone photographing in a bright room is shown, for example, in Japanese Patent Laid-Open No. 189622/1983. This process camera apparatus for bright room photography has a photographing section with a base table carrying a transparent platen having an image forming surface. The process camera apparatus further has a film feeding section provided on one end of the base table. The film feeding section accommodates a photosensitive material in the form of a rolled film and is capable of sliding on the table. The film feeding section is adapted to feed the film into a gap formed between the transparent platen and a light shielding cover on the platen. The space between the platen and the light shielding cover is evacuated by menas of a vacuum pump connected to an evacuating groove formed in the peripheral portion of the platen such as to hold the film in close contact with the film during the exposure. Then, the film is sent to a processing section where the latent image formed on the film is developed.
When conducting the halftone photographing in the known process camera apparatus of the type explained aove, it is necessary to make use of a contact screen which is beforehand fixed to one end of the platen by means of an adhesive tape or the like. On the other hand, the line exposure needs to be conducted without using the contact screen. Therefore, in order to conduct a line exposure before or after a halftone exposure on the same film, it is necessary to attach and detach the contact screen to and from the platen.
In this connection, it is to be noted that the conventional process camera apparatus described above encounters a difficulty in quickly attaching and detaching the contact screen in such a manner as to avoid the breakage of the light-shielded condition of the light-shielded region between the platen and the light-shielding cover and to avoid any offset of the film during the attaching and detaching of the contact screen.
Another problem encountered by the conventional process camera apparatus resides in that it requires a complicated mechanism for correctly mounting the film on the predetermined position on the platen.